Review Question - QID 218383

This patient with Down syndrome presenting with suprapubic discomfort and pain with resolution of his symptoms after a post-void residual bladder scan is performed most likely has volitional urinary retention. Additionally, his holosystolic murmur is attributable to a ventricular septal defect which is commonly associated with Down syndrome.

The organic etiologies of urinary retention can be divided into the broad categories of structural, neurologic, infectious, and medication-induced causes. Structural causes of urinary retention such as urethral stricture, constipation, prostatic hypertrophy, and phimosis lead to impaired urinary outflow, resulting in bladder distention. Neurologic causes of urinary retention, which can result from stroke, diabetic neuropathy, or spinal cord injury, result in impaired relaxation of the urinary sphincter, leading to urine retention. Inflammation in the urinary tract caused by infection can also lead to local obstruction. Finally, anticholinergic medications are a common class of drugs that cause urinary retention as a side effect. After ruling out these causes of urinary retention, volitional urinary retention may be considered. Volitional urinary retention can be seen in patients with Down syndrome, and presents with suprapubic discomfort or pain, lack of volitional bladder emptying for greater than 12 hours, and a normal post-void residual volume. Volitional urinary retention can be treated with urinary rehabilitation consisting of intermittent catheterization, bladder training, and psychotherapy.

Wan, Liu, Liu, and Hwang presented a case report of a child with psychogenic, or volitional, urinary retention. They found that the patient had volitional urinary retention and a urinary tract infection at the same time. They recommended that although it is rare, psychogenic urinary retention be considered in the differential diagnosis of urinary retention, especially in patients with asymptomatic bacteriuria.

Incorrect Answers:
Answer 1: Medication effect of urinary retention can be seen with anticholinergic medications such as diphenhydramine. Anticholinergic side effects include constipation, urinary retention, dry mouth, blurry vision, skin flushing, altered mental status, and sedation. This can be recalled using the “red as a beet, dry as a bone, blind as a bat, mad as a hatter, hot as a hare, and full as a flask” mnemonic. Medication effect is less likely in this patient with isolated urinary retention and whose symptoms resolved with volitional urination.

Answer 2: Prostatic hypertrophy is a common cause of urinary retention in older men due to benign prostatic hypertrophy. Hypertrophy of the prostate gland leads to obstruction of urinary outflow, leading to bladder distention, increased frequency of urination, reduced urination volume, and weak urinary flow. A post-void residual volume would be elevated (>= 200 mL), as patients with urinary obstruction distal to the bladder are unable to completely empty their bladder.

Answer 3: Urinary tract infection can cause urinary retention due to inflammation of the urinary tract leading to temporary obstruction. Patients with urinary tract infections present with urinary frequency, dysuria, and suprapubic pain. Fever may be present. A urinalysis typically shows elevated white blood cell counts (pyuria) and a positive leukocyte esterase and nitrites.

Answer 4: Urinary tract obstruction can occur either proximal or distal to the bladder. Patients with urinary tract obstructions present with lower abdominal or suprapubic pain with ultrasound findings dependent on the location of obstruction. Obstruction proximal to the bladder causes hydronephrosis and/or dilated ureters whereas obstruction distal to the bladder causes a distended bladder and elevated post-void residual volumes.

Bullet Summary:
Volitional urinary retention should be considered in the differential diagnosis of urinary retention in patients with Down syndrome after other causes of urinary retention have been excluded.